How to translate text using browser tools
24 April 2024 Water-seeded rice response to pendimethalin applied at different rates and timings
Aaron Becerra-Alvarez, Kassim Al-Khatib
Author Affiliations +
Abstract

Currently, a limited number of herbicides is available to treat water-seeded rice in California, with widespread resistance to most of those herbicides. Because no resistant grasses showed resistance to pendimethalin, a series of studies were conducted to evaluate water-seeded rice response to pendimethalin. In a field study conducted at the Rice Experiment Station at Biggs, California, in 2020 and 2021, three pendimethalin formulations, a granule (GR), emulsifiable concentrate (EC), and capsule suspension (CS), were applied at 1.1, 2.3, and 3.4 kg ai ha–1 rates, and at 5, 10, and 15 d after seeding onto water-seeded rice. In addition, a greenhouse study was conducted to examine the response of five common California rice cultivars to GR and CS formulation applications. Echinochloa control levels were reduced at 15 d after seeding after use of EC and CS formulations compared with earlier timings. In both years, rice grain yields were increased by 3,014 kg ha–1 after application of pendimethalin at 3.4 kg ai ha–1 when applied at 15 d after seeding compared with 5 and 10 d after seeding, and similar to 1.1 kg ai ha–1 applications. The GR and CS were safer formulations based on a reduction in injury and an increase in grain yields compared to the EC formulation. Differences in seedling vigor across cultivars appeared to incur an advantage after a pendimethalin application. However, most cultivars evaluated for stand reduction and dry biomass demonstrated tolerance to GR and CS formulation applications only after rice reached the 3-leaf stage. In contrast, an application at 1-leaf stage rice reduced stand up to 68%. Application rate, timing, and formulation are important factors to consider if the use of pendimethalin in water-seeded rice is to be pursued.

Nomenclature: Pendimethalin; rice, Oryza sativa L.

Aaron Becerra-Alvarez and Kassim Al-Khatib "Water-seeded rice response to pendimethalin applied at different rates and timings," Weed Technology 38(1), 1-7, (24 April 2024). https://doi.org/10.1017/wet.2024.18
Received: 14 July 2023; Accepted: 15 March 2024; Published: 24 April 2024
KEYWORDS
Herbicide application timing
herbicide rate
medium-grain rice
rice injury
rice yield
short-grain rice
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top